Scientific Report - BEC

The scientific mission 6with stimulating perspectives, also in view of the deep analogies between such systemsand other Fermi systems, like high Tc superconductors and neutron stars. The BoseEinstein condensation of molecules formed starting from a Fermi sea and the superfluidphase have been already realized and the long sought BCS-BEC crossover is now objectof intense theoretical and experimental investigations. In particular, intense researchactivities have been devoted to the study of the hydrodynamic behavior (expansion andcollective excitations), the vortical configurations, the thermodynamic properties, theradio-frequency transitions and the effects of polarization.Also the field of mixtures of different atomic species is becoming a rich area ofresearch. The perspective of generating new molecular configurations with permanentdipole moment and unexplored many-body quantum phases is now becoming realistic.Finally ultracold atomic physics is providing new perspectives of application to quantuminformation processes and precision measurements. These include, among others,the implementation of logical operations with the help of the new available trappingconfigurations, the advanced development of interferometric techniques based on matterwaves and the study of the surface-atom forces.At the same time the theoretical techniques have developed in a significant wayand more sophisticated quantum many-body approaches have been proposed in orderto study the complexity of the new configurations. The theoretical tools have beenmainly based, in the first years, on the use of Gross-Pitaevskii theory for the orderparameter and have proven quite successful, especially to predict the behaviour oftrapped Bose-Einstein condensates at low temperature, both at equilibrium and out ofequilibrium. More recent developments include, among others, quantum simulationsbased on Monte Carlo techniques, quantum models of solid state physics like the Hubbardmodel and new statistical approaches to study fluctuations and correlations. Ingeneral the theoretical approaches in the last few years have become more and moreinterdisciplinary. A significant example is given by the recent progress in the study ofthe surface-atom Casimir-Polder force stimulated by the availability of highly precisemeasurements of the oscillations of Bose-Einstein condensates. At the same time manyof the ideas of dilute quantum gases are becoming of central importance also in solidstate physics and quantum optics. A significant example is given by the physics ofexciton-polaritons, where the concepts of Bose-Einstein condensation and superfluidityare gaining more and more importance.The growth of the field has benefited in a crucial way by the cooperative effortsof experimental and theoretical groups in many laboratories. The aim of the BECCenter is to reinforce the interdisciplinary links of the theoretical research as well as the